As for tyres: Don't get me wrong; I have nothing against using one set of tyres for the entire race. They just don't have to be road relevant. After-all, they do one stint of 11 laps at Le Mans (~150Km) on one set of tyres quite easily. Often they will double stint and even triple stint their tyres, so there is no reason that proper racing tyres cant last a full 45 minute FE race.